Block copolymers of conjugated dienes and lactones

ABSTRACT

Block copolymers formed from a conjugated diene or monovinyl substituted aromatic compound and a lactone using a lithiumcontaining catalyst.

United States Patent [1 1 Hsieh et al.

[ Oct. 9, 1973 BLOCK COPOLYMERS OF CONJUGATED DIENES AND LACTONES [75] inventors: Henry L. Hsieh; Francis X. Mueller,

Jr.; William R. Busler, all of Bartlesville, Okla.

[73] Assignee: Phillips Petroleum Company,

Bartlesville, Okla.

[22 Filed: Feb. 16, 1971 211 App1.No.: 115,793

Related US. Application Data [63] Continuation of Ser. No. 679,978, Nov. 2, 1967,

' abandoned.

[56] References Cited UNITED STATES PATENTS 3,029,221 4/1962 Welch 260/874 3,169,945 2/1965 Hostet tler et al. 260/874 3,225,121 12/1965 Baker 260/874 3,231,635 1/1966 Holden 260/880 3,418,393 12/1968 King 260/874 3,557,255 l/l971 Sharkey 260/880 FOREIGN PATENTS OR APPLICATIONS 676,222 12/1963 Canada .l. 260/783 OTHER PUBLICATIONS Nobutoki et al., Bulletin of the Chemical Society of Japan 40-(8)pp..17411745, 1967 Primary Examiner-James A. Seidleck Attorney-Young and Quigg [57] ABSTRACT Block copolymers formed from a conjugated diene or monovinyl substituted aromatic compound and a lactone using a lithium-containing catalyst.

22 Claims, No Drawings BLOCK COPOLYMERS OF CONJUGATED DIENES AND LACTONES v This application is a continuation of application Ser. No. 679,978, filed on Nov. 2, 1967, now abandoned.

This invention relates to a new and improved block copolymer and a new and improved method for making same.

Heretofore, block copolymers have been formed using two dissimilar monomers such as a conjugated diene and a monovinyl substituted aromatic com pound. By the term block copolymer" what is meant is a copolymer of two dissimilar monomers, the macromolecules of which are composed of at least two segments, usually linear in structure, joined together in an end-to-end relation, one segment being formed predominantly of one monomer and another segment being formed predominantly of another, dissimilar,

monomer. For example, if two dissimilar monomers A and B are employed in making the block copolymer and the resulting block copolymer contains two segments, a macromolecule of this copolymer can be represented by the structure: AAAABBBB.

It has now been found that a block copolymer can be formed using at least one lactone as one monomer andat least one of conjugated diene compounds and monovinyl substituted aromatic compounds as the other monomer, and employing lithium based compounds as the initiator (catalyst).

Therefore, this invention relates to a block copolymer wherein the macromolecules which make up that copolymer contain at least two segments joined-in an end-to-end relationship, at least one segment being formed predominantly of a monomer or monomers mers, or it can have the lactone polymer segment at tached to the terminal ends of the first polymerized monomer or monomers segment. Therefore, the block copolymers of the'invention can be characterized as falling into three distinct classes: (1 a block copolymer of two different polymer segments; (2) a block copolymer of three different polymer segments; or (3) a block copolymer of three different polymer segments wherein the central block is a polymer of a conjugated diene -or monovinyl substituted aromatic compound and the terminal blocks are polymer blocks derived from the lactone. An example of the first type of block copolymer is a poly(conjugated diene)-poly(lactone) polymer. An example of the second type of block copolymer 'is a poly(monovinyl substituted aromatic compound)-poly(conjugated diene )-poly(lactone). An example of the third type of block copolymer is a 'poly( lactone )-poly( conjugated diene )-poly( lactone cations in both the rubber and'plastics fields. The block copolymers of this invention can be used to make fibers and film. For example, the block copolymers of this invention can be formed into a tough, leatherlike film useful as a packaging material and into floor mats, rubberhose, bottles, bowls, and the like.

Accordingly, it is an object of this invention to provide a new and'improved block copolymer.

it is another object of this invention to provide a new i and improvedmethodfor making block copolymers.

from one of the two monomer classes, i.e. lactones or conjugated dienes and/or monovinyl substituted aromatic compounds, and at least one other segment, usually linear, being formed predominantly of at least one monomer from the class of monomers not used to form nyl substituted aromatic compounds are first polymerized a finite amount,'preferably from about 1 to about 100 percent conversion of the monomer or monomers, using a lithium-containing catalyst and thereafter adding to this polymerization reaction mixture after the finite amount of polymerization has been carried out at least one lactone and continuing the polymerization until the finite amount, i.e. from about l to about 100 percent conversion, of the lactone or lactones have been polymerized.

This method provides a block copolymer wherein a polymer block of conjugated dienes or monovinyl substituted aromatic compounds has attached thereto a polymer block derived from the lactone. Depending on the type of lithium initiator employed, the polymer block of conjugated diene or monovinyl substituted aromatic compounds can have the polymer segment derived from the lactone attached to only one end ofthe polymer of the first polymerized monomer or mono- Other aspects, objects, and advantages of this invention willbe apparent to those skilled in the art from the description and append ed claims.

Lactones that can be employed in this invention can be represented by the'formula wherein R, is one of hydrogen and a radical of the formula number of carbon atoms in thesubstituents employed,

if any, is in the range of l to 12, inclusive.

Suitable lactones include beta-propiolactone, deltavalerolactone, epsilon-caprolactone, and lactones of the following acids: 2-methyl-3-hydroxypropionic acid, 3-hydroxynonanoic or 3-hydroxypelargonic acid, 2-dodecyl-3-hydroxypropionic acid, 2-cyclopentyl-3- 3 hydroxypropionic acid, 3-phenyl-3-hydroxypropionic acid, 2-naphthyl-3-hydroxypropionic acid, 2-n-butyl-3- cyclohexyl-3-hydroxypropionic acid, 2-phenyl-3'- hydroxytridecanoic acid, Z-methylcyclopentyl-Iihydroxypropionic acid, 2-methylphenyl-3-hydroxypropionic acid, 3-benzyl-3-hydroxypropionic acid, 2,2-

dimethyl-3-hydroxypropionic acid, 2-methyl-5- hydroxyvaleric acid, 3-cyclohexyl-S-hydroxyvaleric acid, 4phenyl-5-hydroxyvaleric acid, 2-heptyl-4- cyclopentyl-5-hydroxyvaleric acid, 2-methyl-3-phenyl- S-hydroxyvaleric acid, 3-ethylcyclohexyl-5- hydroxyvaleric acid, 4-benzyl-5-hydroxyvaleric acid, 3-ethyl-5-isopropyl-6-hydroxycaproic acid, 2- cyclopentyl-4-hexyl-6-hydroxycaproic acid, 3-phenylo-hydroxycaproic acid, 3-(3,5-diethylcyclohexyl)-5- ethyl-o-hydroxycaproic acid, 4-propylphenyl-6- hydroxycaproic acid, 2-benzyl-5-isobutyl-6- hydroxycaproic acid, 2,2,4-trimethyl-3-hydroxy-3- pentenoic acid, 2-phenyl-6hydroxy--octenoic acid, 2,2-di( l-cyclohexyl)-5-hydroxy-5-heptenoic acid, 2,2- dipropenyl-S-hydroxy-5-heptenoic acid, and the like. Mixtures of two or more of the above lactones can be employed. v The lactone class represents one of the dissimilar monomers employed in this. invention. As explained in more detail in the Examples, infra, the polymerization of the lactones as defined above by use of the lithium catalysts defined hereinafter results in the opening of the lactone ring to'provide a block polymer segment having a polyester structure. The other class of dissimilar monomers employed is the group of conjugated dienes and monovinyl substituted aromatic compounds.

Conjugated dienes that can be employed in this invention are those containing 4 to 12 carbon atoms per molecule, inclusive, for example, 1,3-butadiene, isoprene, l,3-pentadiene(piperylene), 1,3-hexadiene, 2,3-dimethyl-l,3-butadiene, l,3- octadiene, 4-ethyl- 1,3-hexadiene, 4-pheny1-l ,3-butadiene, 6-phenyl-l,3- hexadiene, and the like including mixtures of two or more of these dienes. Preferred conjugated dienes are butadiene, isoprene, and piperylene.

Monovinyl substituted aromatic compounds that can be employed in this invention are those containing known lithium-containing initiator. Preferred initiatorsv are those which correspond to the general formula R'(Li),, wherein R is a hydrocarbon radical selected from the group consisting of aliphatic, cycloaliphatic, and aromatic radicals and combinations thereof, and x is an integer from 1 to 4, inclusive. The R group has a valence equal to the integer x and preferably contain possible to use high molecular weight compounds. Examples of suitable within the scope of the above formula include methyllithium, isopropyllithium, n-butyllithium, tertlithium-containing compounds 4 octyllithium, n-decyllithium, phenyllithiurn, naphthyllithium, 4butylphenyllithium, p-tolyllithium, 4-phenylbutyllithium, cyclohexyllithium, 4-butylcyclohexyllithium, 4-cyclohexylbutyllithium, dilithiomethane, 1,4- dilithiobutane, 1,10-dilithiodecane, l ,ZO-dilithioei'cosane, 1,4-dilithiocyclohexane, 1,4-dilithio-2-butene, 1 ,8-dilithio-3-decene, l ,4-dilithiobenzene, l ,5- dilithionaphthalene, 1,2-dilithio-l ,2-diphenylethane, 1,5-dilithioanthracene, 1 ,2-dilithio-l ,8- diphenyloctane, 1,3,5-trilithiopentane, 1,5,15-trilithioeicosane, 1,3,S-trilithiocyclohexane, 1,2,5- trilithionaphthalene, l ,3 ,5 -trilithioanthracene, 1,3,5 ,8-tetralithiodecane, l ,5 10,20-tetralithioeicosarie, l,2,3,5-tetralithiocyclohexane, 1,2,3 ,5- tetralithio-4-hexylanthracene, and the like. Other preferred catalyst include reaction products between the compounds of the formula R(Li), as disclosed hereinabove and one of a divinylaromatic or a trivinylaromatic compound containing 1 or 2 benzene rings of alkyl vsubstituted benzene rings, the total of the alkyl substituents on any dior trivinylaromatic compound not exceeding 12 carbon atoms. Examples of suitable vinylaromatic compounds for reaction with the organolithiurn catalyst include divinylbenzene, trivinylnaphthylene, divinylbiphenyl, and the like.

ln the preparation of the block copolymers of the invention wherein three different polymer segments are produced, one being a central polymer block of conjugated diene or monovinyl aromatic compound and the other blocks being a polymer segment derived from the lactone, those lithium initiators which contain more than one activelithium atom per molecule are suitable. These catalysts provide a central polymer segment of the conjugated diene or monovinyl aromatic compound having attached to the terminal ends of the polymer segment an active Li atom. Catalysts such as the -reaction productof lithium with methylnaphthalene and isoprene, followed by solubilizing the reaction product with butadiene (LIMl-B) and catalysts such as a lithiumstilbene adduct are suitable.

When preparing the block copolymers of this invention, thecatalyst level for the polymerization of the conjugated diene and/or monovinyl substituted aromatic compound can vary widely but is generally in the range of from about 1 to about 20, preferably from about 2 to about 10, gram millimoles per 100 grams of total monomers to be polymerized, i.e. all the conjugated diene and/or monovinyl substituted aromatic monomers as well as all the lactone monomers. The catalyst level is generally not changed when the conjugated dienes and/or monovinyl substituted aromatic compounds have been polymerized to the desired extent and the lactone or lactones are added for polymerfrom l to 20, inclusive, carbon atoms, although it is ization. Thus, the catalyst level for the polymerization of the conjugated diene and/or monovinyl substituted aromaticcornpound is generally the catalyst for the entire polymerization process. Generally, the amount of initiator or initiators used in making the block copolymer of this invention will be that which is sufficient to effect the polymerization of substantially all monomers charged, be they charged at the same time or in sequence one after the other.

The amount of each dissimilar monomer employed in making the block copolymers and therefore to comprise the final block copolymers of this invention can vary widely but generally the amount of conjugated diene and/or monovinyl substituted aromatic compound will be in the range of from about 1 to about 99 weight percent while the amount of lactone employed will also be in the range of from about 1 to about 99 weight percent, both weight percentages being based on the total weight of the total monomers (conjugated dienes and/or monovinyl substituted aromatic compounds and lactones) employed in the polymerization process. When a monovinyl substituted aromatic compound or compounds are employed in admixture with one or more conjugated dienes, said mixture can employ the components thereof in any desired weight percent ratio.

When preparing the block copolymers of the invention, the polymerization conditions for polymerizing both first and second monomers include a temperature in the range of from about to about 300F. The pressure is conveniently adjusted at a level sufficient to maintain the polymerization reaction mixture substantially in the liquid phase. The time for polymerization of the first monomer can be from about 1 minute to about 100 hours, and the time for polymerization of the second monomer can be from about 1 minute to about 100 hours. The reaction can be carried out in the presence of a diluent. Paraffins, cycloparaffins, and aromatic hydrocarbons each having from 4 to 10 carbon atoms per molecule inclusive, acyclic and cyclic ethers having 2 to 6 carbon atomsper molecule, inclusive, and mixtures of the above are suitable.

The block copolymers of this invention are prepared by a two-step process wherein thefirst step is the polymerization of the conjugated diene and/or monovinyl substituted aromatic compound using the lithiumcontaining catalyst and, optionally, suitable diluent. The polymerization of the monomers is allowed to continue to any desired conversion percentage up to and including 100 percent conversion of the monomers to polymer. After the desired amount of monomer conversion has been reached, all or part of the lactone monomer or monomers can be added to the polymerization reaction mixture and polymerization continued to the desired conversion of the lactone monomer including 100 percent conversion of that monomer to polymer. It is essential that the conjugated diene and/or monovinyl aromatic compound monomer be polymerized first because the conjugated diene and/or monovinyl substituted aromatic compound polymer-Li structure is believed to serve as the catalyst for the polymerization of the lactone monomer whereas if the lactone monomer is polymerized first the lactone polymer-OLi structure does not provide a reactive site for the subsequent polymerization of the conjugated diene and/or monovinyl substituted aromatic compound. Thus, if the lactone monomer is polymerized first the block copolymer cannot be formed.

The block copolymers of this invention can also be prepared in a multi-step process wherein a conjugated essential that the conjugated diene or dienes and monovinyl substituted aromatic compound or compounds be polymerized first because of considerations stated above. By the above, after the lactone is polymerized, a copolymer is produced which contains two or more blocks, e.g. a terpolymer containing a polystyrene block, a polybutadiene block, and a polylactone block.

The block copolymers of this invention can be recovered in any conventional manner such as by catalyst deactivation by the addition of alcohol or other known deactivating agents, separation of the polymer from solution such as by vaporization of the diluents thereby leaving the polymeric product, and drying the polymer. The block copolymers can be compounded in any conventional manner with conventional additives such as carbon black, pigments,-antioxidants, and other known stabilizers.

EXAMPLE I A block copolymer with a first block of a homopolymer of butadiene and a second block of a polyester of epsilon-caprolactone was prepared in a two-step process using n-butyllithium as the polymerization catalyst. The recipe was as follows:

TABLE I Step 1: Cyclohexane, parts by weight 780 l,3-Butadiene, parts by weight 50 n-Butyllithium, mhm 5 Temperature, F. 158 Time, hours 1 Conversion, 100

Step 2: Epsilon-caprolactone, parts by weight 50 Temperature, F. 158 Time, hours 24 Conversion, 100

* mhm gram millimoles per I00 grams monomer Cyclohexane was charged to the reactor first. The reactor was then purged with nitrogen after which the butadiene was added and then the butyllithium. The temperature was adjusted to 158F. and after 1 hour, polymerization of the butadiene was essentially complete. The reaction mixture was cooled to room temperature, the caprolactone added, the temperature was adjusted to 158F., and the mixture was agitated for 24 hours during which time the caprolactone polymerized. The

(ML-'4 at 212F.), was blended with poly(epsiloncaprolactone). The blend was prepared using 10 grams of each polymer. The sampls were cut into small pieces, 200 ml of chloroform was added, and the mixture was agitated at C. for 18 hours. All material was dissolved. The solvent was then evaporated.

The poly(epsilon-caprolactone) was prepared as follows:

TABLE II Cyclohexane, parts by weight 780 Epsilon-caprolactone, parts by weight n-Butyllithium, mhm 10 Temperature, F. 4l

A tough, leather-like polymer was obtained by evaporation of the diluent.

Samples of the block copolymer (4 grams each) and also of the polymer blend grams each) were separately treated with 200 ml of acetone by agitating the mixtures about l5 hours at 70C. Other samples were treated in a similar manner with cyclohexane. The mixtures were cooled to ice temperature and filtered to remove undissolved material. The dissolved material was recovered from the solutions by evaporation of the solvent. The recovered, dissolved material was weighed and the percent extracted was calculated. Results were as follows:

TABLE III Per Cent Sample Solvent Extracted Blend Acetone 54 Block copolymer Acetone 8.3 Blend Cyclohexane 40 Block copolymer Cyclohexanc 98 EXAMPLE ll Block copolymers were prepared from butadiene and epsilon-caprolactone using a procedure similar to that described in Example I, i.e., the polybutadiene block was prepared first and the epsilon-caprolactone was then added and polymerized. Two runs were made using different butyllithium levels. Each of the polymers was compound in a conventional manner using a gum stock recipe. The stocks were cured 30 minutes at 307F., and tensile strength and elongation were determined. Polymerization recipes and results were as follows:

TABLE IV Step I: Cyclohexanc, parts by weight 780 780 1.3-Butadiene. parts by weight 50 5O n-Butyllithium. mhm 3 4 Temperature, F. 158 l58 Time. hours L5 1.5 Conversion. 100 lOO Step 2: Epsilon capmlactone, parts by weight 50 50 Temperature, F. 7 I58 158 Time. hours 24 24 Conversion, 1' I00 I00 Tensile. psi (1 l l 120 740 Elongation. (I) 430 3l0 Same as Table l (I) ASTM D 4l2-62T The products were leather-like in texture and were also somewhat elastic. The gum stock recipe employed for compounding the polymers was as follows:

TABLE V Parts by Weight Polymer I00 Zinc oxide 3 Stearic acid 2 Sulfur l.75

N-cyclohexyl-2-benzothiazolesulfenamide 1 EXAMPLE III Different ratios of butadiene and epsiloncaprolactone were employed for preparing block copolymers. The procedure was essentially the same as that described in Example I. The solvent was cyclohexane and 780 parts by weight were used per 100 parts by weight of monomers. The n-butyllithium level was 5 mhm (same as Table l). The first step of the process was conducted at 158F. for 90 minutes. This was for the preparation of the polybutadiene block. After 'addition of the epsilon-caprolactone, polymerization was continued at 122F. for 24 hours. Results were as follows:

TABLE VI Epsilon- Butadiene. caprolactone. Conversion, Run Parts by Wt. Parts by Wt. (l) l 30 7O 78 2 5O 50 94 3 7O 30 89 l) Based on total monomers charged Block copolymers were formed in all cases. When these stocks are cured in a gum stock recipe, the polymer from run 1 is a leather-like product wherein samples with at least 50 weight percent butadiene content are elastomeric. Products increase in elasticity as the butadiene content is increased.

EXAMPLE lV Two different dilithium catalysts, one prepared by reacting lithium with methylnaphthalene and isoprene and solubilizing the product with butadiene (LlMl-B) and the other a lithium-stilbene adduct, were employed for preparing block copolymers from butadiene and epsilon-caprolactone. The products contained a central block of polybutadiene and two terminal blocks of poly(epsilon-caprolactone). The polymerization recipes and results were as follows:

TABLE VII l 2 Step 1: Cyclohexane, parts by weight 780 780 l.3-Butadiene. parts by weight 50 50 LIMI-B. mhm 6 Lilhium-stilbcne adduct. mhm 6 Temperature. F. 122 I22 Time. hours 1.5 1.5 Step 2'. Tetrahydrofuran, parts by weight 35 35 Epsilon-eaprolactone, parts by weight 50 50 Temperature. "F. 122 I22 Time, hours 20 20 Conversion. l) 92 88 (1) Based on total monomers charged Same as Table l The lithium-methylnaphthalene-isoprene adduct solubilized with butadiene was prepared as follows:

TABLE VIII Lithium wire. grams 2 Methylnaphthalene. ml l4.2 Diethyl ether. ml 47 Temperature. F. 22 Time. hours 68 After the lithium and methylnaphthalene had reacted for 68 hours, the temperature was raised to 41F l2 ml of isoprene was added, and the reaction was continued 1 hour. A total of 50 ml of butadiene was added in TABLE IX Lithium wire, g. atom 0.08 trans-Stilbene, mole 0.03 Diethyl ether, ml 90 Tetrahydrofuran, ml 10 Temperature, F. I22

Time, hour 7 l Molarity of the reaction mixture, determined by titration with 0.1 N HCl, was 0.383.

EXAMPLE V Homopolymers of butadiene and epsiloncaprolactone were prepared using the same catalyst level in each run. Polymerization recipes were as follows:

TABLE X l 2 Cyclohexane, parts by weight 780 780 1,3-Butadiene, parts by weight 100 Epsilon-caprolactone, parts by weight 100 nButyllithium, mhm 8 8 Temperature, "F. 158 A 158 Time, hours l.5 25 Conversion, 1* lOO lOO Same as Table I When conducting a polymerization, cyclohexane was charged to the reactor first. The reactor was then purged with nitrogen after which the monomer was added and then the butyllithium. Each reaction was ter- Same as Table I The reaction was terminated by addition of antioxidant solution as in runs 1 and 2 and the product was coagulated in isopropyl alcohol, separated, and dried. A white solid, homogeneous in appearance, was obtained.

In this run, the catalyst level was equivalent to 8 mhm for each step, the same as that used for the preparation of each of the polymers in runs 1 and 2. In step 2, the catalyst was polymer-Li instead of butyllithium. This catalyst level produced a liquid polybutadiene block and a solid poly(epsilon-caprolactone) block.

An attempt was made to prepare a solution blend of the products from runs 1 and 2 of Table X. Twenty grams each of the liquid polybutadiene and solid poly(epsilon-caprolactone) were placed in a vessel with 400 ml of chloroform and agitated at 158F. for 24 hours. This treatment caused both polymers to disminated by the addition of approximately one part by weight per 100 parts by weight polymer of 2,2- methylene-bis(4-methyl-6-tert-butylphenol), introduced as a 10 weight percent solution of the antioxidant in a mixture of equal parts by volume of isopropyl alcohol and toluene. g

The product from run 1 was a liquid. It was recovered by evaporating the diluent. The polymer was then dried.

The product from run 2 was a solid. As the polymer formed, it precipitated from the reaction mixture. At the conclusion of the polymerization and following addition of the antioxidant, the diluent was poured off and chloroform was added to dissolve and remove the polymer from the reactor. The chloroform was then evaporated and the remaining polymer product was dried. This polymer was a tough, leather-like solid.

These data show that at this catalyst level, a liquid polymer was obtained from the conjugated diene polymerization and a solid polymer was obtained from the lactone polymerization.

A block copolymer was a first block of-polybutadiene and a second block of epsilon-caprolactone was prepared according to the invention using n-butyl-lithium as the catalyst. The recipe was as follows:

TABLE XI 3 Step 1: Cyclohexane. parts by weight 780 1,3-Butadiene, parts by weight 50 n-Butyllithium, mhm 4 Temperature, F. 158 Time, hours sulting from blending procedure of runs 1 and 2 of Table X was entirely different from the block copolymer prepared in run 3 of Table XI.

Since liquid polybutadiene and solid poly(epsiloncaprola'ctone) were found to be incompatible, a solution blend of rubbery (solid and not liquid) polybutadiene of about 45 Mooney value (ML-4 at 212F.) and the solid poly(epsilon-caprolactone) of run 2 of Table X was prepared. This rubbery type of polybutadiene was more compatible with the solid poly(epsiloncaprolactone). Fifteen grams of each homopolymer was added to 400 ml of chloroform and the mixture was agitated at 158F. for 18 hours. Both polymers dissolved as a result of this treatment. The chloroform was evaporated and the blend was dried in an oven. This blend is designated as run 4.

The blend prepared in run 4 and the block copolymer from run 3 of Table Xl were compounded in a conventional manner using gum stock recipes. The stocks were cured 30 minutes at 307F. and tensile strength and elongation were determined. Compound recipes and results of physical tests were as follows:

(1) As in Example ll These data show that the block copolymer containing a normally liquid polybutadiene as. the polybutadiene block has a much higher tensile and elongation than the blend containing a more solid rubbery polybutadiene. It was unexpected to find that the block copolymer containing a normally liquid polybutadiene as the polybutadiene block had higher tensile and elongation than a blend using a more solid rubbery polybutadiene.

The conjugated diene block imparted elastomeric character to the block copolymer and also rendered it vulcanizable. Poly(epsilon-caprolactone) it tough, is not vulcanizable, and will cold draw but does not have the recovery characteristic of elastomers.

EXAMPLE V] A block copolymer with a first block of a homopolymer of styrene, a second block of a homopolymer of butadiene, and a third block of a polyester of epsiloncaprolactone was prepared in a three-step method using sec-butyllithium as the catalyst. The recipe was as follows:

TABLE Xlll Step 1: Cyclohexane, parts by weight 780 Styrene, parts by weight 25 sec-Butyllithium, mhm" 4 Temperature, F g 158 Time, hours l Step 2: l,3-Butadiene, parts by weight 50 Temperature, "F I58 Time, hours L5 Step 3: Epsilon-caprolactone, parts by wt. 25 Temperature, F l58 Time, hours 24 Same as Table l The materials were charged in the following order: cyclohexane, styrene, sec-butyllithium, Lil-butadiene, epsilon-caprolactone. The polymerization was terminated by addition of 1 part by weight per lOO'parts by weight polymer of 2,2'-methylene-bis(4-methyl-6-tertbutylphenol) as a weight percent solution of the antioxidant in isopropyl alcohol. The polymer was recovered by coagulation in isopropyl alcohol.

The polymer was solid and tests gave the following results:

TABLE XIV Conversion based on the total weight of all three monomers, 7i 9] Tensile, psi (1) 4240 Elongation, (1') M90 (1) ASTM D4l2-62T Reasonable variations and modifications are possible within the scope of this disclosure without departing from the spirit and scope thereof.

I claim:

1 A block copolymer of at least two dissimilar monorners,.the macromolecules of which consist essentially and third segments are polyester polymers derived wherein R is one of hydrogen and a radical of the formula when R, is the-specified radical no R is attached to the carbon atom to which the radical is attached; each R is one of hydrogen, a saturated aliphatic, a saturated cycloaliphatic, .or an aromatic radical, or combination thereof; n is an integer which can be 1, 3, or 4; and the total number of carbon atoms in the substituents employed, if any, is in the range of l to 12.

2. The block copolymer of claim 1 consisting essentially of two segments wherein one segment is a homopolymer block of a conjugated diene having from 4 to 12 carbon atoms per molecule, and the other segment is said polyester polymer attached to one end of the homopolymer block of said conjugated diene.

3. The block copolymer of claim 2 wherein said conjugated diene is at least one of butadiene, isoprene, or piperylene, and R is hydrogen.

4. The block copolymer of claim 3 wherein the conjugated diene is butadiene and the lactone is epsiloncaprolactone.

5. The block copolymer of claim 1 consisting essentially of two segments, the first segment being a copolymer of at least one of said conjugated dienes and at least one of said monovinyl-substituted aromatic compounds, and the second segment being a polyester polymer derived from at least one of said lactones attached to one end of the first segment.

6. The block copolymer of claim 5 wherein said conjugated diene is at least one of butadiene, isoprene, piperylene, said monovinyl-substituted aromatic compound is styrene, and R in the formula is hydrogen.

7. The block copolymer of claim 6 wherein said lactone is epsilon-caprolactone.

8. The block copolymer of claim 1 consisting essentially of three segments, one segment being a polymer of at least one of said conjugated dienes having attached to each end thereof a polyester polymer derived from at least one of said lactones, the two polyester segments being derived from the same lactone monomer or monomers.

9. The block copolymer of claim 8 wherein said conjugated diene is at least one of butadiene, isoprene or piperylene and Rio the formula is hydrogen.

' 10. The block copolymer of claim 9 wherein the first from the same lactone which is epsilon-caprolactone.

11. The block copolymer of claim 10 wherein said conjugated diene is butadiene.

12. The block copolymer of claim 1 consisting essentially of three segments, the first segment being a polymer of at least one of said monovinyl-substituted aromatic compounds, and having attached to one end thereof a second segment of a polymer of at least one of said conjugated dienes, the polymer segment of said said conjugated diene is butadiene, and said lactone is epsilon-caprolactone.

17. An article of manufacture made from the block copolymer of claim 1.

18. An article of manufacture made from the block copolymer of claim 5.

19. An article of manufacture made from the block copolymer of claim 8.

20. An article of manufacture made from the block copolymer of claim 12.

21. A film formed of the block copolymer of claim 1.

22. A film formed of the block copolymer of claim 2. 

2. The block copolymer of claim 1 consisting essentially of two segments wherein one segment is a homopolymer block of a conjugated diene having from 4 to 12 carbon atoms per molecule, and the other segment is said polyester polymer attached to one end of the homopolymer block of said conjugated diene.
 3. The block copolymer of claim 2 wherein said conjugated diene is at least one of butadiene, isoprene, or piperylene, and R is hydrogen.
 4. The block copolymer of claim 3 wherein the conjugated diene is butadiene and the lactone is epsilon-caprolactone.
 5. The block copolymer of claim 1 consisting essentially of two segments, the first segment being a copolymer of at least one of said conjugated dienes and at least one of said monovinyl-substituted aromatic compounds, and the second segment being a polyester polymer derived from at least one of said lactones attached to one end of the first segment.
 6. The block copolymer of claim 5 wherein said conjugated diene is at least one of butadiene, isoprene, piperylene, said monovinyl-substituted aromatic compound is styrene, and R in the formula is hydrogen.
 7. The block copolymer of claim 6 wherein said lactone is epsilon-caprolactone.
 8. The block copolymer of claim 1 consisting essentially of three segments, one segment being a polymer of at least one of said conjugated dienes having attached to each end thereof a polyester polymer derived from at least one of said lactones, the two polyester segments being derived from the same lactone monomer or monomers.
 9. The block copolymer of claim 8 wherein said conjugated diene is at least one of butadiene, isoprene or piperylene and R in the formula is hydrogen.
 10. The block copolymer of claim 9 wherein the first and third segments are polyester polymers derived from the same lactone which is epsilon-caprolactone.
 11. The block copolymer of claim 10 wherein said conjugated diene is butadiene.
 12. The block copolymer of claim 1 consisting essentially of three segments, the first segment being a polymer of at least one of said monovinyl-substituted aromatic compounds, and having attached to one end thereof a second segment of A polymer of at least one of said conjugated dienes, the polymer segment of said conjugated dienes having also attached thereto a polyester polymer derived from at least one of said lactones.
 13. The block copolymer of claim 12 wherein said monovinyl-substituted compound is styrene and said conjugated diene is at least one of butadiene, isoprene, or piperylene.
 14. The block copolymer of claim 13 wherein R in the formula is hydrogen.
 15. The block copolymer of claim 14 wherein said lactone is epsilon-caprolactone.
 16. The block copolymer of claim 12 wherein said monovinyl-substituted aromatic compound is styrene, said conjugated diene is butadiene, and said lactone is epsilon-caprolactone.
 17. An article of manufacture made from the block copolymer of claim
 1. 18. An article of manufacture made from the block copolymer of claim
 5. 19. An article of manufacture made from the block copolymer of claim
 8. 20. An article of manufacture made from the block copolymer of claim
 12. 21. A film formed of the block copolymer of claim
 1. 22. A film formed of the block copolymer of claim
 2. 